Studio spot lamp



June 23.11942. J, Q ROSE f 2,287,328

STUDIO sPoT LAMP Filed Feb. s, 1941 2 sheets-sheet 1 lamentan Jess6R05?.

a/-Mpw Jun@ 23,1942. J, ROSE 7 2,287,328

STUDIO SPOT LAMP Filed Feb. 5, 1941 2 Sheets-Sheet 2 [2z L'ez Zar. EJes; Cl Rose.

Patented June 23, 1942 UNITED STATES ortica STUDIO SPOT LAMP ApplicationFebruary s, 194i, serial N. 377,154 4 claims. (ol. 24o-47) Thisinvention relates generally to studio spot lamps such as are used inmotion picture studios for illumination of sets. A

Studio spot lamps are ordinarily designed with ventilation openingsarranged to permit circulation of air through the lamp casing forcooling purposes. It is always an object to arrange these openings insuch a Way that air circulation and consequent cooling will be ample.

Lamps of this type are also sometimes designed with the purpose in Viewof permitting use under rainfall conditions (either natural orartificial) without liability of water getting inside the casing throughthese ventilation openings. A still further design requirement is theprovision of light trap arrangements at ventilation openings to preventescape of light through the lamp casing, since stray light on a set isar detriment to good. photography.

The object of the present invention is to provide an improved andsimplified studio lamp construction designed for maximum aircirculation, for eifective exclusion of water, and for eiective trappingof light at all openings.

The present invention will best be understood without preliminarydiscussion by referring at once to the following detailed description ofone illustrative embodiment, reference for this purpose being had to theaccompanying drawings, in which:

Fig. 1 is a transverse'vertical section taken on line l-l of Fig. 2;

Fig. 2 is a section taken on broken 'lines 2-2 f Fig. l;

Fig. 3 is a top plan View of the lamp;

Fig. 4 is a detail section 'taken on line 4 4 of Fig. l; and

Fig. 5 is an enlarged section taken on line 5-5 of Fi-g. 2,

The lamp of the present invention has a cylindric casing ill, extendingbetween circular front and rear end frame members II and I2,respectively, and has at the bottom a rectangular housstructure or boxi3. In the present illustrative embodiment, the end frame members Il andI?. are sheet metal spinnings, each having an inwardly turned annularflange I6 defining a circular opening for a hinged door. A rear door 'iis receivable inside the rear door opening, being hinged at I8 on rearend frame I2. A front door I9 is receivable inside the front dooropening, being hinged at 2li on front end frame li. These doors may beof any suitable construction, not necessary here to describe in detail.However, it may be mentioned that the rear door is shown as providedwith a manual knob 22, and will preferably be provided with any suitabletype of latch mechanism, not here detailed. And front door I9 isequipped with the usual lens 23, preferably and here shown as theFresnel type, and may have a somewhat forwardly projecting annular angepart 24 equipped with diffuser brackets r25.

End frame members I I and I2 are formed with .iarginal inwardly Yturnedflanges 2t within and to which certainparts'of the cylindric side wallconstruction are received' and secured.

The rectangular bottom structure I3 of the lamp includes flangedendframe extensions 2l secured to the bottoms vof members II and I2, andintegral side and 'bottom wall members 32 and' which extend, between endframe extensionsZl and are received inside and secured lto theanges' 28of the latter. As 'here illus- 'tra-tively shown, the inner edges ofbottom members 3S define an air inlet aperture in which is received alight-trap structure lit, the latter comprising vertical side walls llisecured to the edges of bottom members 33, and transverse chevron-shapedlight baiiles ft2 extending between walls ai. The bailies G2 arerelatively closely spaced, so as to prevent any light escapingdownwardly through the bottom of the lamp, while-at the same timeaiiording passageways for free circulation of air into the interior ofYthe lamp.

The cylindric side wall Il! of the lamp comprises an outer series ofinwardly facing circumferential channels 5 and anvinner series ofoutwardly facing circumferential channels 66, the channels of bothseries-being spaced longitudinally of the lamp by a spacing intervalwhich is somewhat less vthan `the width of a channel. The inwardlyfacing channels i5 comprise webs il and inwardly extending flanges 48,and the outwardly facing channels 46 comprise webs 49 and outwardlyextending langes '50.. The outer and inner channels 45 and Il@ arestaggered, i. e., the channels of each series are positioned oppositethe spaces between the channels 'of the other series. The inner andouter channels l5 and @i6 are in close radial juxtaposition, the edgesof the res .ective anges 'i8 and 5! preferably lbeing in substantialalinement. Each channel being substantially wider than the spacingbetween the channels, its twoflanges are spaced beyond or overlapsomewhat the near anges of the two next adjacent channels of the otherseries. Thus the two contiguous flan-ges of each associated pair ofinner and outer channels define a tortuous air circulation passageway,which is of such a character as to exclude light from leakingtherethrough. These tortuous air circulation passageways extendcircumferentially around the cylindric part of the lamp casing, and areof sufficient total cross sectional area as to assure free and fullcirculation of air into and out of the lamp, with the result that thelamp will remain at low operating temperature even after prolonged use.

The lower ends of the outer and inner channels 45 and 46 are here shownto abut a deflector flange 55 that extends inwardly and upwardly fromthe upper edges of the side wall members 32 of bottom structure I3, andthat has an outwardly and upwardly bent portion 56 positioned inside thelower end portions of the channels.

As here illustratively shown, the series of outer channels 45 terminateat each end frame of the lamp in a half-channel 45a, the web of which isreceived inside end frame flange 25.

Alternate channels 45 and 46 are connected each to the next by bracketmembers 58, such as shown in Figs. 3 and 4. These bracket members 58 ashere shown comprise portions 6I secured as by welding to the centralportions of the webs 48 of inner channels 46, and angle portions 62extending from each end of portion 6| and engaging and secured as bywelding to the flange and a portion of the web of an adjacent outerchannel 45, all as will be clearly understood from inspection of Fig. 4.As here shown (see Fig. 1) there are four circumferentially spaced rowsof such interconnecting bracket members 60, and

these taken together integrate the inner and outer series of channelsinto a unitary side wall structure. To further brace the side wallstructure, I preferably employ a plurality of longitudinally extendingsheet metal strips 10, laid flat on the outer surfaces of the outerchannels and received underneath and secured to the marginal flanges 26of the two end frame members Il and I2. The channels 45 are secured tolongitudinally extending strips 'l0 in any suitable Way, as by welding.As here shown, there is one of the strips 'I8 at the top of the lamp,and to this top strip lll is secured a carryingV handle H for the lamp.Two of the strips 18 are at opposite sides of the lamp, in line with itscentral axis, and to these are preferably secured the trunnion mountingsl2 for the usual yoke arms, fragmentarily indicated at 13. Two furtherstrips l0 are lpreferably positioned at the lower ends of the channels45, as appears in Figs. 1 and 5.

A pair of parallel longitudinal lamp carriage guide rods 88 are hereshown as mounted on brackets 8l secured to end frames ll and l2, asshown in Fig. 2. Slidable on these rods 88 is a lamp carriage 82, of anysuitable or conventional type, adapted to carry the usual incandescentlight globe 83. Carriage 82 also supports a spherical reflector 84 tothe rear of light globe 83, said reflector being designed to receivelight from the filament 85 of globe 83 and to reiiect it back to a focusin the plane of the filament 85.` The lamp carriage 82, globe 83 andreflector 84 may be conventional and will require no detailedconsideration herein. Fig. 1 shows a focusing mechanism suitable forsliding carriage 82 along guide rods 80, and comprising a bracket arm 86extending from carriage 82, a link 8l pivotally connected to arm 88, acrank arm 88 pivotally connected to link 81 and mounted for rotation onside wall 32, and an exterior operating handle 89. Such a focusingmechanism is described and claimed in my prior patent, Re. 21,089,issued May 16, 1939. It will be understood that rotation of handle 88will operate the crank arm 88 and link 81 to slide lamp carriage 82longitudinally on rods 80, thus adjusting the position of globe 83 withreference to the lens 23 of the lamp, so as to adjust the focus.

The lamp of the present invention is now described as not only of simpleconstruction and of attractive appearance, but assures a maximum of aircirculation through the lamp without possibility of light escapingthrough the side walls of the lamp casing. The construction as describedis especially effective in excluding downpouring water from the interiorof the lamp. Water falling on the lamp, either vertically, or at asubstantial slant angle, is received by the outwardly facingcircumferential channels 45, travels downwardly around said channels todeilector flange 55, and is discharged from the lamp over the latter. Ifany water gets into the inwardly facing channels 45, it likewise travelsdownwardly to the deflector flange 55, a slight spacing being preferablyprovided between the lower ends of the channels 45 and flange 55 topermit escape of the water from said channels down the flange 55, as isclearly shown in Fig. 5. The lamp thus combines the features ofsimplicity of construction, maximum air circulation, effective lighttrapping, and complete exclusion of water.

One preferred and illustrative embodiment of the invention has now beenshown and described; it will be understood, however, that this is forillustrative purposes only, and that various changes in design,structure and arrangement may be made without departing from the spiritand scope of the invention, or of the appended claims.

I claim:

1. In a lamp having a pair of spaced front and rear -generally circularend frames: a ventilated, water excluding and light trapping cylindricwall construction extending between and mounted at opposite ends on saidend frames, said cylindric Wall construction comprising inner and outerrows of spaced circumferential channels extending longitudinally betweenthe end frames and closely radially juxtaposed to one another, each suchchannel comprising a web and a pair of flanges extending in the samedirection from opposite edges of said web, the channels of the outer rowfacing inwardly and the channels of the inner row facing outwardly, andthe channels of each row being positioned opposite the spaces betweenthe channels of the other row, and the spacing between channels beingsuch that the two flanges of the individual channels of each of the rowsextend beyond and receive between them the adjacent anges of the twoadjacent channels of the other row, and means interconnecting all saidchannels to form an integrated structure.

2. In a lamp having a pair of spaced front 'and rear generally circularend frames: a ventilated, water excluding and light trapping cylindricwall construction extending between and mounted at opposite ends on saidend frames, said cylindric wall construction comprising inner and outerrows of spaced circumferential channels extending longitudinally betweenthe end frames and closely radially juxtaposed to one another, each suchchannel comprising a web and a pair of flanges extending in the samedirection from opposite edges of said web, the channels of the 4outerrow facing inwardly and the channels of the inner row facing outwardly,and the channels of each row being positioned opposite the spacesbetween the channels of the other row, and the spacing between channelsbeing such that the two flanges of the individual channels of each ofthe rows extend beyond and receive between them the adjacent anges ofthe two adjacent channels of the other row, and relatively narrowsupporting brackets connecting the individual channels of each row toeach of the adjacent channels of the other row at a plurality of pointsspaced circumferentially around the channels.

3. In a lamp, the combination of a pair of spaced front and reargenerally circular end frames, a cylindric wall structure extendingbetween and mounted at opposite ends on said end frames and comprisinginner and outer rows of spaced circumferential channels extendingcircularly around the sides and top of the lamp, said rows of channelsextending longitudinally between the end frames and being closelyradially juxtaposed to one another, each such channel comprising a weband a pair of flanges extending in the same direction from oppositeedges of said web, the channels of the outer row facing inwardly and thechannels of the inner row facing outwardly, and the channels of each rowbeing positioned opposite the spaces between the channels of the otherrow, and the spacing between channels being such that the two flanges ofthe individual channels of each `of the rows extend beyond and receivebetween them 'the adjacent flanges of the two adjacent channels of theother row, a box mounted on and extending between the bottom sides ofthe two end frames closing the lamp at the bottom, and deflector membersextending along the side edges of the box and positioned opposite thelower ends of said channels to divert any water travelling downwardly insaid channels outside the side edges of said box.

4. In a lamp, the combination of a pair of spaced front and reargenerally circular end frames, a cylindric wall structure extendingbetween and mounted at opposite ends on said end frames and comprisingan interlocking channel formation extending circumferentially around thesides and top of the lamp, said interlocking channel formation providingchannels formed and arranged to trap water falling on the lamp and toconvey any such water to the lower ends of said channels, a box mountedon and extending between the bottom sides of the two end frames closingthe lamp at the bottom, and deflector members extending along the sideedges of the box and positioned opposite the lower ends of said channelsto divert any water travelling downwardly in said channels outside theside edges of said box.

JESS C. ROSE.

